Two complaints recently investigated by the Advertising Standards Authority (ASA) have been upheld - meaning that on three occasions in just over a year, imagery used by the retailer has been deemed irresponsible.

Models appearing to promote the company's knitwear, bodysuits and thigh-high socks appeared vulnerable and overtly sexual, with the photographs objectifying women, said the complaints that were filed.

In one image a model was shown from the side wearing only a jumper with her bottom half appearing naked as she reclined on a bed with her legs in the air; in another, a model was depicted from the front and had her legs open and another showed her from behind in a kneeling position.

The retailer, whose products are manufactured in California, is known for its use of 'normal women' in its provocative campaigns, who often star make-up free on unmade beds and ordinary sofas.

The ASA's adjudication states that American Apparel 'said they did their best to abide by the standards of the industry as well as creating authentic, honest and memorable images relevant to their customer base.'

The ASA concluded that the ads breached its Code, writing: 'We considered there was a voyeuristic quality to the images, which served to heighten the impression that the women were vulnerable and in sexually provocative poses. For the reasons given, we considered the ads were likely to cause serious offence to visitors to American Apparel's website.'